Kevin, I think we are closer than you think... Honestly, I was just responding to the question from the earlier poster about why small coax is not suggested for speaker cables, not arguing whether it would/should be used for that purpose.
1. I am running standard 12 AWG speaker wire. I had it for many years before I knew about Monoprice, but it's essentially the same stuff. Nothing I have heard has convinced me to go larger or more exotic.
2. As I said earlier, RG-6 or similar should handle 400+ W, it's a just a bit lossy for long runs and the small inner conductor trashes the damping factor. Whether that matters to you or anyone else I cannot say. In DBT ages ago a group of us could easily pick out 24 gauge from 12 gauge speaker cables, and small coax has conductors about that size. It was within statistical error from 16 gauge to 12 gauge for about a 20' run.
3. If a stage crew (or whomever) cut a speaker line I would grab my spare, or solder (more likely wrap splice or wire-nut it if I had only minutes) it back together, but RG-whatever would certainly work fine for most runs and live sound. Not sure I would use it on the kW bass amps I used back then, but for the HF it'd be fine. I agree! It would not be my first choice, but it would work. For horn tweeters, it probably wouldn't even be noticed in a critical listening situation. On a big bass crate, the loss of amp control would make the bass a bit tubby. The audience would probably love it.